Vibrating grinding mill



July 9, 1968 c. G. COOLEY VIBRATING GRINDING MILL 5 Sheets-Sheet 1 Filed Sept. 22, 1965 R 8 m H m M W F m 1 4 M e 0 B July 9, 1968 c. 5. COOLEY VIBRATING GRINDING MILL 5 Sheets-Sheet 2 Filed Sept. 22, 1965 INVENTOR, Cecil G. Cooley BY ATTORNEYS July 9, 1968 c. e COOLEY 3,391,872

VIBRATING GRINDING MILL Filed Sept. 22, 1965 5 Sheets-Sheet 5 33 lNV vTOR.

Cecil G. Cooley ATTORNEYS July 9, 1968 c. e. COOLEY 3,391,872

VIBRATING GRINDING MILL Filed Sept. 22, 1965 5 Sheets-Sheet 4 INVENTOR. Cecil G. Cooley Qw% 5140M ATTORNEYS July 9, 1968 c. G. COOLEY 3,391,872

VIBRATING GRINDING MILL Filed Sept. 22, 1965 5 Sheets-Sheet 5 mvsmorz. Cecil G. Cooley ZWM ATTORNEYS United States Patent "cc 3,391,872 VIBRATING GRINDING MILL Cecil George Cooley, 5730 E. 17th Ave., Denver, Colo. 80220 Filed Sept. 22, 1965, Ser. No. 489,238 15 Claims. (Cl. 241-176) ABSTRACT OF THE DISCLOSURE Vibrating grinding mill for size reduction of granular material having feed inlet and discharge outlet distant therefrom with contained grinding media applying impact forces to material advancing from inlet to outlet. Mill has resilient support and is mounted for rotation about horizontal axis. Vibrating means for selective positioning and directing straight line forces toward mill along its axis of rotation. Mill may rotate as an idler or by .power drive with straight line forces directed against declining side when rotating as idler.

This invention relates generally to grinding mills and more particularly to rotary grinding mills containing grinding media, such as balls, pebbles, rods or the like, which subject the contained charge of material to impact grinding and attrition in the rotary action of the mill.

Many materials require size reduction in preparation for industrial processing and a variety of apparatus has been devised to accomplish the desired size reduction. Some employ wet grinding methods in which the solids to be treated are introduced into a liquid carrier vehicle, such as water. Dry grinding operations also are performed, particularly when it is desirable to avoid wetting of the reduced material. The present invention is adapted for dry grinding and some wet grinding treatments.

In the usual dry grinding practice, it is necessary to the efficiency of the operation that the feed material is essentially dry, particularly when the size reduction provides a final product of extremely fine size, as for example, minus 100 to minus 300 mesh. The finely divided material becomes mixed with the moisture present in the feed if there is any appreciable amount of contained or adhering moisture, and forms a pasty or sticky mass which is difficult to move or advance through the mill, and as a consequence, impedes the efficiency of the size reduction and discharge.

The apparatus of the present invention provides vibratory forces to the material in conjunction with the rotary action which combine to prevent previously mentioned sticky material from clinging to and building up on the media and mill walls thus increasing the throughput of material and lower retention time in treatment. In addition, the rapid, progressive movement lessens the opportunity of over-grinding and thus improves the overall efiiciency of the operation.

It is an object of my invention to provide simple, durable and efiicient apparatus for size reduction of granular materials which is particularly adapted for dry grinding treatment of material having an unusual or excessive amount of surface or adhering moisture.

Another object of this invention is to provide a rotary mill for dry and wet grinding operations which combines the application of controlled and directed vibratory forces to a rotary action in a rotary mill which may be driven at a preselected rate of rotation, or may be mounted for free rotation and rotated by the controlled direction of the vibratory forces.

A further object of the invention is to provide a simple, durable and eflicient grinding mill having a high capacity treatment in a mill of small size using a relatively low 3,391,872 Patented July 9, 1968 power supply and which is adapted for various types of wet and dry grinding operations.

Other objects reside in novel details of construction and novel combinations and arrangements of parts.

The practice of my invention has been illustrated in the accompanying drawings. In the drawings, in the several views of which like parts bear similar reference numerals,

FIG. 1 is an end elevation view of a grinding mill embodying features of my invention;

FIG. 2 is a top plan view of the grinding mill shown in FIG. 1 with the vibrating assembly removed;

FIG. 3 is a partial sectional view of the bearing assembly used in the mill illustrated in FIG. 1;

FIG. 4 is a vertical sectional view of the mill illustrated in FIG. 2 showing the direction of rotation of the mill and the contained grinding media;

FIG. 5 is an end elevation view of an alternative embodiment of my invention with a second alternative drive arrangement shown in dash lines;

FIG. 6 is an end elevation view of another mill embodiment of my invention particularly suitable for vertical vibrating forces.

FIG. 7 is a side elevation view of another mill embodiment of my invention showing a single inlet and an end peripheral discharge distant therefrom; and

FIG. 8 is a partial sectional view of another mill embodiment using a grate discharge.

A floor or base-supported arrangement of a mill embodying features of my invention is illustrated in FIGS. 1 through 4 wherein a generally rectangular base 1 is shown and includes parallel lengthwise and lateral beams which are rigidly attached or secured as an integral assembly. A resilient member such as a coil spring 2 fits in a seat member disposed on each corner of base 1. A pair of flanged upright plates 3 and 4, hereinafter referred to as the forward and rear plates, respectively, as shown, are rigidly connected by beams 5 and are supported at their ends by the springs. A seat member 6 is attached to the outer face at the end of each plate and has a collar portion 6 which nests in the top of each spring so that the forward and rear plates 3 and 4 are resiliently supported on base 1. A bearing assembly 7 is provided approximately centrally of each plate and is of special construction described more fully hereinafter.

The grinding portion of the mill preferably includes a cylindrical hollow shell 8 which may be provided with a suitable lining 22 (FIG. 4) if desired. Shell 8 terminates at its ends in trunnions 9 (FIG. 3) which are fitted in the bearing assemblies 7 so as to dispose shell 8 for rotation about a horizontal axis of rotation designated X, and shell 8 is balanced for relatively free rotation. The bearing assemblies 7 are of particular construction to allow free rotation of shell 8 about the axis of rotation X and will be described more fully hereinafter with reference to FIG. 4. Shell 3 is thus resiliently supported on base 1, springs 2, plates 3 and 4 and bearing assembly 7.

A feed inlet (not shown) is disposed at each end of shell 8 and discharges into the interior passage 10 through each respective trunnion for discharging the material to be ground into the hollow interior of the shell. A perforated or apertured peripheral discharge 12 is disposed in shell 8 intermediate of the feed inlets for the discharge of ground product of the feed charge advancing to the central discharge from the introduction point at the end of the mill.

Referring particularly to FIG. 1 a vibrating assembly 13 is shown mounted above shell 8 by attachment at the top of forward and rear plates 3 and 4. Vibrating assembly 13 generates vibrating grinding forces against the resilient support of shell 8 and thus to material advancing from the inlet to the outlet of shell 8.

A series of spaced apertures are provided in plates 3 and 4 adjoining their tops which aline with similar spaced apertures adjoining the bottom of vibrating assembly 13 with a plurality of nut and bolt assemblies extending therethrough for fastening vibrating assembly 13 to plates 3 and 4. This fastening arrangement allows for shifting the vibrating assembly laterally in either direction to change the vibratory forces or to substitute vibrating assemblies having diiferent force characteristics as will be described more fully hereinafter.

Various types of vibrating units may be used but a preferred unit is of the unbalanced-shaft type which directs straight line forces in a plane. An example of a suitable commercial vibration unit is the Syncrornatic Vibrator manufactured and sold by the Link-Belt Company.

Vibrating assembly 13 is shown as including a pair of unbalanced shafts 19 and 20 which extend substantially the length of shell 8 and are adapted for rotation in opposite directions by a drive mechanism (not shown). Unbalanced shafts 19 and 2! are disposed in spaced relationship and on an acute angle with the horizontal.

The angular displacement of shafts 19 and 20 is timed so that on the downward stroke of its cycle (as shown in FIG. 1) the centrifugal forces of rotating shafts 19 and 20 combine to direct a straight line force downwardly along line 14 which passes through the axis of rotation X. Shafts 19 and 20 will rotate to an upward stroke of its cycle (opposite of that shown in FIG. 1). The centrifugal forces combine to direct a straight line force upwardly along line 14. At both intermediate positions of shafts 19 and 20 between the upward stroke and the downward stroke the centrifugal forces are opposite and equal.

This straight line force is in a plane including line 14 due to the lengthwise extent of shafts 19 and 20 and is normal to the axis of rotation X as it passes therethrough.

More specifically straight line force along line 14 as shown in FIG. 1 is a resulting vector comprised of horizontal and vertical components of force which is directed in the upper declining quadrant of the shell. As previously discussed provision is made for shifting assembly 13 laterally to change the vibratory forces. With each positioning of assembly 13 the straight line forces along line 14 will be in a plane forming an acute angle with a horizontal plane through axis of rotation X. The vibratory forces generated by assembly 13 along line 14 will cause the grinding mill (FIG. 1) to rotate in a clockwise direction when charged with grinding media.

Referring now to FIG. 3, there is show the details of the bearing assembly 7 mounted on trunnion 9. Assembly 7 includes a self-aligning roller bearing 16 in forcefitted relationship over the outer surface of trunnion 9 and enclosed by a casing which includes an inner housing member 17 and an outer housing member 18 bolted to member 17. Roller bearings 19 are held between said housing members and bearing assemblies 7 permit free rotation of shell 8 in response to the vibratory forces of vibrator 13.

Hollow shell 8 contains a charge of grinding media as is illustrated in FIG. 4 which comprises grinding balls 21. Any grinding media, such as rods, pebbles, balls or the like, is suitable. The rotation of the shell 8 in the clockwise direction and the grinding media in the counter-clockwise direction results from the vibratory action in a manner described more fully hereinafter. The inner surface of shell 8 preferably includes liner members 22 preferably having circumferentially spaced lifter members 23 on their exposed surfaces.

The general operation of the grinding mill described in FIGS. 1 through 4 is as follows. Granular material is fed through feed inlets and trunnion passages where it falls into the end of the mill. Vibrating assembly 13 is rigidly attached to plates 3 and 4 which are in turn resiliently supported and said plates are subjected to continuous vibrations when vibrating assembly 13 is operating.

Shell 8 being attached through trunnions 9 to plates 3 and 4 is thereby vibrated and these vibratory forces cause shell 8 to rotate in one direction. The vibratory forces are such that the direction of rotation of the grinding media 21 is opposite to the direction of rotation of the shell 8 and increases impact and attrition. The 'vibratory forces also assist in advancing the granular material from the end of the mill toward the central peripheral discharge 12, and it is tum-bled and vibrated in .shell 8 as it progresses from the inlets to the peripheral discharge and undersize discharges as soon as it reaches the discharge position.

In this action, the granular material is reduced in size by impact as the particles are passing between the grinding media and also by the attrition effect of the particles contacting each other during movement. The vibration effect substantially increases these grinding actions and the mounting arrangement distributes the vibrating action throughout the interior extent of the mill.

This mill has been found particularly suitable for use as a dry grinding mill and a typical operation will effectively grind coarse sand from sand pits which has substantial amounts of adhering moisture which usually becomes sticky but passes readily through my mill to produce a very fine sand at preselected sizes in the minus 14 to minus 200 mesh size ranges.

For some applications, it is desirable to drive the mill with a power unit which will rotate the grinding mill at a constant or variable speed. In FIG. 5 there is shown a vibrating mill including a horizontally disposed cylindrical shell or housing 38 mounted for rotation on support structure 31 which is resiliently mounted on pairs of springs 32 at the corner and sub-base 33 with a vibrating assembly 43 mounted above housing 38 to direct vibratory forces along line 34 in the same manner as described with reference to FIGS. 1 through 4. A motor and speed reducer unit 44 is coupled by a belt drive to housing 38 to rotate housing 38 as shown. As an alternative, a chain drive 47 shown in dash lines may be used for certain applications.

One preferred arrangement of the vibrating assembly is illustrated in FIG. 6 wherein a vibrating assembly 13a having unbalanced shafts 19a and 20a is shown. Shafts 19a and 20a are disposed horizontally in spaced relationship above shell 8 and an equal distance from the axis of rotation X. The centrifugal forces of the upward and downward strokes of the cycle generate vertical straight line vibratory forces along line 14a which are in a plane normal to the axis of rotation. The shifting of assembly 13a to the right or left will in each instance provide straight line vibratory forces directed vertically in a plane forming a perpendicular with a horizontal plane through the axis of rotation.

Referring now to FIGS. 7 and 8, other embodiments of vibrating mills in accordance with my invention are shown. In FIG. 7 there is shown a grinding mill 48 supported for rotation by support structure 41 which is resiliently mounted on springs 42 at the corner and sub-base 43 with the vibrating assembly 53 mounted above the mill 48 in the same manner as previously described. This embodiment has a feed inlet 50 at one end and an apertured peripheral discharge 52 in the shell distant from the feed inlet and preferably adjacent its opposite end.

As another alternative to FIG. 7 the grinding mill may I be of the grate discharge type which is illustrated in FIG. 8. The mill 58 includes a discharge trunnion 59 and a grate discharge member 60. The hollow shell 61 maybe lined with a suitable liner 62 if desired. This embodiment is particularly suitable for handling a large capacity charge in a small volume mill and will preferably be driven by a motor in an arrangement of the type shown in FIG. 5.

Although I have illustrated specific embodiments of my invention, various modifications will occur to those skilled in the art. Therefore, I do not desire my invention to be limited to the specific details illustrated and described, and I intend by the appended claims to cover all modifications which fall within the spirit and scope of my invention.

I claim:

1. A vibrating grinding mill for reducin a granular material from a coarser size to a finer size as said material is advanced therethrough, comprising resilient support means, grinding means having a feed inlet at one end and a discharge outlet distant therefrom and containing grinding media for applying impact forces to the advancing material, said grinding means including a hollow housing supported by said resilient means and mounted for rotation about a substantially horizontal axis, and vibrating means exteriorly of the housing constructed and arranged to impart strai ht-line, vibratory forces directed toward the rotary housing along its axis of rotation.

2. A vibrating grinding mill for reducing a granular material from a coarser size to a finer size as said material is advanced therethrough, comprising resilient support means, grinding means having a feed inlet at one end and a discharge outlet distant therefrom and containing grinding media for applying impact forces to the advancing material, said grinding means including a hollow housing supported by said resilient means and mounted for rotation about a substantially horizontal axis, vibrating means exteriorly of the housing constructed and arranged to impart straight-line, vibratory forces directed toward the rotary housing along its axis of rotation, and means for rotating said housing about its axis of rotation.

3. A vibratory grinding mill for reducing a granular material from a coarser size to a finer size as said material is advanced therethrough, comprising resilient support means, grinding means having a feed inlet at one end and a discharge outlet distant therefrom and containing grinding media for applying impact forces to the advancing material, said grinding means including a hollow housing supported by said resilient means and mounted for free rotation about a substantially horizontal axis, and vibrating means exteriorly of the housing constructed and arranged to impart straight-line, vibratory forces directed toward the rotary housing along its axis of rotation and thereby imparting rotation to the housing directed oppositely to the rotation of grinding media within the housing.

4. A vibratory grinding mill for reducing a granular material from a coarser size to a finer size as said material is advanced therethrough, comprising resilient support means, grinding means having a feed inlet at one end and a discharge outlet distant therefrom and containing grinding media for applying impact forces to the advancing material, said grinding means including a hollow housing supported by said resilient means and mounted for free rotation about a substantially horizontal axis, and vibrating means exteriorly of the housing constructed and arranged to impart straight-line, vibratory forces directed toward a declining quadrant of the housing along its axis of rotation and thereby imparting rotation to the housing directed oppositely to the rotation of grinding media within the housing.

5. A mill as defined in claim 1, in which the housing has a peripheral discharge.

6. A mill as defined in claim 1, in which the housing has a feed inlet at opposed ends and a peripheral discharge intermediate the ends.

7. A mill as defined in claim 1, in which the housing has a grate and an adjoining discharge outlet distant from its inlet.

8. A mill as defined in claim 1, in which the vibrating means are supported from said resilient means above said housing, and the straight-line vibratory forces are directed in a plane forming an acute angle with a horizontal plane through the axis of rotation.

9. A mill as defined in claim 1, in which the vibrating means are supported from said resilient means above said housing for selective location in positions directing vibratory forces at different angles toward the housing along its axis of rotation,

19. A mill as defined in claim 1, in which said vibratory forces are directed vertically toward said housing along its axis of rotation.

11. A mill as defined in claim 1, in which said vibratory forces are directed in a plane normal to the axis of rotation of said housing.

12. A mill as defined in claim 1, in which said vibratory forces include straight line resulting vector forces directed in a plane normal to the axis of rotation of said housing.

13. A mill as defined in claim 1, in which said resilient means are disposed in thrust-resistant relation to said vibratory forces.

16. A vibrating grinding mill for reducing a granular material from a coarser size to a finer size as said material is advanced therethrough, comprising a supporting structure, a resilient base mounting for said supporting structure, grinding means having a feed inlet at one end and a discharge outlet distant therefrom and containing grinding media for applying impact forces to said advancing material, said grinding means including a hollow housing on said support structure mounted for rotation about a substantially horizontal axis, and vibrating means secured on said supporting structure above said housing for directing straight line forces in a plane forming an acute angle with a horizontal plane coextensive with and through said axis of rotation and to the declining side of said housing.

15. A mill as defined in claim 1, having drive means for rotating said housing at selected speeds.

References Cited UNITED STATES PATENTS 2,170,768 8/1939 Schieferstein 241 2,469,484 5/ 1949 Thirnan 241175 2,809,47 3 10/ 1957 Heaphy 241175 2,911,160 11/1959 Hartwig 241175 3,091,435 5/1963 Pease 241175 FOREIGN PATENTS 633,699 8/1936 Germany.

GERALD A. DOST, Primary Examiner. 

